A Blog About Stone Gathering, Tumbling and Polishing, and Rocks and Landscapes, from New Zealand – With Musical Interludes (john.tumblestone@gmail.com)
I spent a few days based in Riverton early in May, on a stone collection trip. Two of my aims were to spend more time on Gemstone Beach and to explore the beach further to the west, near a place called McCracken’s Rest. I took an extra suitcase down with me so that I could carry more stones home with me than I usually do on the plane. I ended up bringing back 26.5 kgs of carefully selected beach pebbles.
Day One at Riverton saw me drive out to McCracken’s Rest, 36 kilometres from Riverton. This is a roadside lay-by and viewpoint eight kilometres west of Orepuki and Gemstone Beach.
McCracken’s Rest on the coast of Te Waewae Bay, northwest of Orepuki. The Waiau River mouth is further northwest, where the Te Waewae Lagoon is created by a stone bar. Source: Google Maps
Just northwest of McCracken’s Rest is the start of Te Waewae Lagoon.Source: Google Maps
McCracken’s Rest in relation to Riverton, 36 kms away. Source: Google Maps
On YouTube is this clip which gives a good sense of the roadside lay-by (although at 1:24 Stewart Island is misidentified – it is in fact well hidden in the mist – the piece of land referred to as Stewart Island is really the headland between Monkey Island and Cosy Nook, the headland just south of Orepuki – see the third last photo, bottom left, in the group below).
The information panel and viewpoint at McCracken’s Rest, looking out on Te Waewae Bay
The viewpoint lies between Orepuki and Tuatapere
On one side of the information panel is a map of the area
The photographer and the photograph
The Waiau River is the source of many of the stones on the beaches here
Te Waewae Bay
McCracken’s Rest and Gemstone Beach in relation to Monkey Island and Cosy Nook
The other side of the information panel features a historical time spiral for Tuatapere
The spiral of history
The beach between Orepuki and McCracken’s lies below cliffs all the way along so access is very difficult. At the viewpoint at McCracken’s Rest, I hopped over the fence and carefully made my way down the steep slope to the beach below.
The viewpoint at McCracken’s Rest – the best entry point to the beach, though unofficial
On the way down to the beach, layers of stones are exposed, their roundness suggesting they were probably laid down by the Waiau River or some other river long ago
Detail of exposed stones
The scene at the bottom of the slope, beneath McCracken’s Rest viewpoint, looking north-west
The beach at McCracken’s Rest is similar to the beach further south-east, back towards Gemstone Bach and the Waimeamea Lagoon. There is a low bank of stones above the high tide mark, along with a wide scattering of drift wood. Closer to the waves, there are sandy patches and drifts of smaller stones.
Looking north-west, towards Fiordland
Looking south-east, towards Gemstone Beach which is about 6 to 7 kilometres away
Sand and stones on the beach near McCracken’s Rest
There is no scarcity of stones
There are slightly more larger stones here than further south-east on the beach, back near Gemstone Beach
Stones on the beach near McCracken’s Rest
Looking back up to the McCracken’s Rest viewpoint
I spent two and a half hours there – the day was largely fine and with little wind, which allowed the sandflies to be active. I slowly walked (and fossicked) just over a kilometre north-westwards to the start of the Te Waewae Lagoon (created by the Waiau River trying to find a path to the sea). The actual mouth of the Waiau River can vary in position along this gravel bar, depending on the countervailing forces of the river’s flow and the stones thrown up by the sea.
This is as far as I walked, the start of the Te Waewae Lagoon. The actual mouth of the Waiau River is another 6 or 7 kilometres to the north-west.
Looking along the gravel bar that has created the Te Waewae Lagoon
Gravel cliff just at the soulth-eastern end of Te Waewae Lagoon
Detail of the gravel cliff. Very likely to one of the intermediate sources of stones for this beach and further south-east
There seemed to be more slightly larger and less rounded stones here than at Gemstone Beach, and I did not see as many colourful ones. I also found no hydrogrossular garnets although there were fossil worm cast stones.
Well-defined fossil worm casts in a large stone, left on the beach
A large dark red jasper
Probably a stone of volcanic origin
Gogeous black, grey and white stone, with fault lines, just a little too big to tumble polish
Large colourful stone
Maybe a kind of argillite
Another large stone with fossil worm casts, though they do not show the segmentation pattern as the previous one
Probably a stone of volcanic origin
I collected quite a few stones on the beach but later discarded many of them after careful re-examination. This was partly because I found much better stones later at Gemstone Beach and on the Riverton beaches. I still ended up bringing home 2.3 kilograms of stones from the beach between McCracken’s Rest and Te Waewae Lagoon.
Sorting through the stones picked up at the beach below McCracken’s Rest
A quartz, at first glance very similar to an agate
Breccia stone
Probably a quartzite stone
The fossil worm casts in this stone are raised, being made of harder material than the rest of the stone
Before returning to Riverton, I drove up to Fishing Camp Road, about two and a half kilometres north-west of McCracken’s Rest, and drove along it to the shores of the Te Waewae Lagoon. This brought me to the landward side of the lagoon, near a handful of fisher huts and a boat ramp. The stones there were dirty and slimy and uninteresting – but one could gaze across the lagoon at the gravel bar separating the lagoon from the sea and see the kind of interesting ones to be found between there and Gemstone Beach.
Just up the road from McCracken’s Rest, towards Tautapere
The beach from McCracken’s Rest to the Waiau River – Fishing Camp Road turns off the Orepuki-Tuatapere Highway (99) halfway between. Source: Google Maps.
Fishing Camp Road leads to fisher huts on the landward side of the Te Waewae Lagoon. Source: Google Maps.
Te Waewae Lagoon, fisher hut to right, boat ramp to left. Waiau River mouth out of sight in the distance
The stones on this side of the lagoon are muddy and slimy.
Looking back along the shores of the lagoon towards McCracken’s Rest (out of sight). I had earlier walked to the spot where the cliffs come down at the head of the lagoon.
Looking across the lagoon to the gravel bank, beyond which is Te Waewae Bay
For a number of years before I retired from the University of Waikato, I assisted with the supervision of Gemma Piercy-Cameron’s PhD thesis. Gemma was finally successful in completing her grand project, Baristas: The Artisan Precariat, a few months ago. Currently, Gemma is a Lecturer in Sociology and Social Policy at the University of Waikato (see her Staff Profile). I presented her with nine milestones to mark her accomplishment.
The following letter accompanied Gemma’s milestones (photos added here):
Why Nine Stones? Nine is seen to have philosophical significance, due to its unique numerical attributes. In the Hebrew tradition, for instance, Nine represents truth, since it reproduces itself when multiplied. Multiply any number by 9, then add the resulting digits and reduce them to a single digit, it always becomes a 9 again, e.g., 6 x 9 = 54, 5 + 4 = 9; 23 x 9 = 207, 2 + 0 + 7 = 9. Another attribute of Nine is that when added to any other number and then that number is reduced to a single digit, it always comes back to itself, as if nothing was added at all. For example, 5 + 9 = 14, 1 + 4 = 5; 7 + 9 = 16, 1 + 6 = 7. Nine is the Triple Triad, consisting of three times three, and so is seen as symbolic of completion, fulfillment, attainment, the beginning and the end, the ultimate whole number. Appropriate to recognise the completion of a PhD!
Stone #1 “Coffee”
Stone 1 “Coffee”
Other side of Stone 1 “Coffee”
Unknown type, collected at Riverton (Southland) July 2017, polishing completed September 2017. Polishing brought out the creamy swirl that reminded me so strongly of coffee and latte art that I knew it was destined for you.
Back Beach, Riverton, Stewart Island in background (left)
Western end of Back Beach, Riverton
Gull and stones, Back Beach, Riverton
Stone #2 “Positioned Sparkle”
Stone 2 “Positioned Sparkle”, full of quartz and large mica crystals
Same face of Stone 2 “Positioned Sparkle”
Reverse face of Stone 2 “Positioned Sparkle”
Detail of some of Stone 2’s large mica crystals
Mica-rich pegmatite rock, collected at Joyce Bay (near Charleston, Buller District) March 2017, unpolished. Your thesis reflects who you are, and sparkles as it is turned to be viewed from different positions. Different things will be seen in it depending on who views it from which position.
Joyce Bay on left – from a postcard
Source: Google Maps
Northern end of beach at Joyce Bay, where Stone 2 was found
Joyce Bay rock, full of quartz and mica
Joyce Bay, near Charleston, West Coast
Stone #3 “Effort”
Stone 3 “Effort”
Stone 3 “Effort”
Detail of Stone 3 “Effort”
Mudstone, collected at Riverton July 2017, polishing completed September 2017. This stone started millions of years ago as a number of sediment layers, being compressed by weight and heat. Your thesis consists of layers of effort and activity, building on each other, one layer being the foundation for the other. Over time, effort becomes more focused, refined, productive, until completion is reached.
Henderson Bay, Riverton
Stone #4 “Complexity”
Stone 4 “Complexity”
Detail of Stone 4 “Complexity”
Detail of Stone 4 “Complexity”
Stone 4 “Complexity”
Jasper, with silica, collected at Riverton February 2018, polishing completed August 2018. Reality is complex and resists analysis. Analysis is hard labour.
Stone #5 “Depth”
Stone 5 “Depth”
Detail of Stone 5 “Depth”
Detail of Stone 5 “Depth”
Stone 5 “Depth”
Pale green Quartzite, collected at Orepuki (Southland), April 2016, polishing completed November 2017. Depth of understanding and insight is gained by multi-method qualitative research.
The beach near Orepuki
The beach near Orepuki
Stone #6 “Found Worthy”
Stone 6 “Found Worthy”
Stone 6 “Found Worthy”
Stone 6 “Found Worthy”
Stone 6 “Found Worthy”
Stone 6 “Found Worthy”
Detail of Stone 6 “Found Worthy”
Banded Agate, collected on Birdlings Flat (Canterbury) June 2016, polishing completed September 2016. Agate is formed from quartz crystals growing in layers so small they can barely be seen. The layers build up to fill cavities in sediments left by gas bubbles in volcanic rocks. This particular banded agate is very unusual (the only one of its kind I have found) – when held up to the light, it is apparent that the bands are not smooth but have intricate and delicate lace-like waves in them. This stone will have originated in the Alps, been washed down a Canterbury river, and swept along the coast to be deposited on Birdlings Flat which abuts Banks Peninsula. Your thesis has survived close examination in the light of others’ assessments, and has been found to be worthy of scholarly esteem.
Birdlings Flat beach, the western part of Kaitorete Spit abutting Banks Peninsula
Kaitorete Spit, a 25 kms long gravel bank, looking towards Banks Peninsula, separating Lake Ellesmere from the Pacific Ocean
From the car park at Birdlings Flat
Birdlings Flat beach and Banks Peninsula
Stone #7 “Patterns”
Stone 7 “Patterns”
Detail of Stone 7 “Patterns”
Detail of Stone 7 “Patterns”
Stone 7 “Patterns”
Unknown type (possibly a type of schist?), collected at Riverton February 2018, polishing completed August 2018. Research identifies patterns and layers and makes sense of them for others.
Beach Past The Back Beach, Riverton
Beach Past The Back Beach, Riverton
Beach Past The Back Beach, Riverton
Beach Past The Back Beach, Riverton
Beach Past The Back Beach, Riverton
Beach Past The Back Beach, Riverton
Stone #8 “It takes time to construct an interesting story”
Stone 8 “It takes time to construct an interesting story”
The largest fossil worm cast in Stone 8 “It takes time to construct an interesting story”
A smaller fossil worm cast in Stone 8 “It takes time to construct an interesting story”
Detail of Stone 8 “It takes time to construct an interesting story”
Argillite, a hardened mudstone, with fossil worm casts, collected at Orepuki February 2018, polishing completed August 2018. This argillite started as mud under the sea 250-280 million years ago. The interesting linear features were left behind by ancient worms who had ingested lighter coloured mud. All pieces of scholarly writing, including your thesis, are like fossils of your thoughts at a particular period of time, persisting in existence even as you go on to other thoughts and activities.
Gemstone Beach, Orepuki
Gemstone Beach, Orepuki
Stone #9 “Well Travelled and Wide Ranging”
Stone 9 “Well Travelled and Wide Ranging”
Detail of Stone 9 “Well Travelled and Wide Ranging”
Detail of Stone 9 “Well Travelled and Wide Ranging”
Stone 9 “Well Travelled and Wide Ranging”
Quartzite, stained with iron, collected at Budleigh Salterton (Devon, England) May 2018, polishing completed August 2018. These Devon stones are identical to rocks found in Brittany in France. Some 200-250 million years ago, Brittany was mountainous and rivers drained from it northwards across the Triassic desert, across what was to become the English Channel. The quartzite rocks were tumbled into pebbles and eventually deposited as pebble beds outcropping on cliffs at the beach of Budleigh Salterton village. Good PhD research takes time, has gone places, and has a broad base of experience and reflective thought.
Just out of a 3lb borax burnishing tumble, 43 newly-polished stones from a Riverton beach.
I collected these stones at a beach I call the “Beach Past the Back Beach” at Howells Point, Riverton, in March 2019. When you reach the end of the road at Howells Point, there is a track up the sand dunes. Down the other side is this beach, which stretches for maybe 900 metres further westwards. Many of these stones were found at the far eastern corner, the area circled in this photo:
Riverton’s “Back Beach” is the stretch along the last part of the road that winds along the coast. If you walk over the dunes from there, you come to the “Beach Past the Back Beach”.
These are not particularly spectacular stones, though some are really interesting. Not all have polished perfectly, some have scratches and holes in them, but I polished them because of their intriguing colours and patterns.
Photos of a selection of these newly-polished stones:
Since I got back home from Southland at the end of March, I have been tumble-polishing stones collected from Gemstone Beach near Orepuki (see here for an account of their collection). On 28 April the polishing process finished for one 4lb barrel containing a mix of different types of interesting and colourful stones. These are the subject of this Post.
These stones are not “gems” in the sense of precious and sparkling jewel-like stones such as diamonds and sapphires. But I actually find them to be much more interesting and intriguing, many of them a mystery as to how they got the way they are. In this sense they are the true gems of Gemstone Beach.
This batch of 95 Gemstone Beach stones started their tumbling in 320 grit and then were tumbled in pre-polish and pro-polish tin oxide before a final week in a burnishing tumble with borax. This is how they ended up:
95 Gemstone Beach stones just out of the final Borax tumble
To look at some of these stones more closely…
One of them is a gorgeous quartzite (my identification of it as a quartzite is based on what I learned at Vince Burke’s Museum at Birdlings Flat):
Quartzites are not as common along the south coast as at Birdlings Flat in Canterbury, but I always find a couple of excellent ones at Riverton and Orepuki. They polish well, often have great colour, have interesting veins through them, and there’s a depth to them that makes them intriguing.
Two of the stones look like marble. Again, I can usually find one or two such stones on a collecting expedition, and I have started to keep an eye out specifically for them:
Marble-looking stone #1
Other side of marble-looking stone #2
Patterns in marble-looking stone #2
Marble is limestone subjected to heat and pressure. Veined and patterned marble is often created when a pure white original marble is cracked or shattered and the spaces between the fragments are filled with other materials. As I noted, I don’t know whether these stones are marble or not, but they certainly remind me of it. Note: April 2025 – These stones are indeed NOT marble but are iron-stained quartz. They tumble polish well and often have interesting patterns.
Over the last three years, I have found maybe half a dozen stones like this one:
I have always suspected that they are petrified wood. However, I am beginning to wonder whether they are in fact a type of jasper. I have always found them in association with dark red jasper stones, at Waikaka and on the south coast, and sometimes paler forms of jasper have been nearby. They don’t have the obvious characteristics of petrified wood, like wood grain, but it has been their light brown colour that seemed wood-like. And they have a brittleness like jasper has. Irrespective of what they are, I like them. Note: April 2025 – These stones are indeed jasper, not petrified wood.
This next stone has a very unusual set of linear features:
It could be quartz with inclusions of some other mineral. Another stone with a different kind of “inclusion” is this small green one which has specks of pink:
The next four stones have various kinds of fascinating patterns. The first stone has a breccia section at the top. The second stone is about three-quarters red with various small inclusions. The third has alternating light and dark layers plus a white halo. The fourth is actually one of my three or four favourites in this group of 95, due to its patterns of shades of grey (the last four photos below are of this stone, and they do not do it justice).
One of the most unusual stones I picked up off Gemstone Beach in March is this one:
I think these are coral fossils in this stone. I have not done much reading on fossils but I have been recently been going through a book which I found in my local library, “Rocks and Fossils” by Arthur Busbey, Robert Coenraads, David Roots and Paul Willis (2007). On page 211, the authors mention that “corals are among the most common fossils on Earth”. They refer to “rugose corals” whose characteristics could account for some features of the fossils in this stone. Rugose corals have the following structure:
A fossilised coral like this would leave circular impressions of different sizes in a stone, depending how far each individual coral is eroded away from its top. Something like this would account for the patterns on the stone (above) I found on Gemstone Beach. Note: April 2025 – I suspect this stone is not fossil coral but rather an orbicular variety of some rock.
Sometimes I come across stones with pink in them. It is thought that the presence of manganese or cobalt could cause this. For example, rhodochrosite and rhodonite owe their pink colour to manganese, and cobalt ore is often pink. Here are two pink stones found on Gemstone Beach in March: Note: April 2025 – These are thulite.
Finally, five other interesting and colourful stones:
All of these stones illustrate the wide range of stones that can be found on Gemstone Beach that tumble polish well.
DEVELOPMENTS IN MY STONE COLLECTING AND POLISHING STRATEGY
I have become aware that I have changed my approach to collecting and polishing stones over the past three years. Initially, I collected any stone that looked like it might be interesting. I often thought to myself, “Let’s see what happens to this one.” I then tried to produce a completely smooth polished stone, with no flaws. I put each stone through all the stages of tumbling, starting with 100 grade silicon carbide grit. This meant that the stones lost a lot of their material by the end of the process. Along the way, I also discarded stones that had pits or cracks that were not worn away – I was looking for a perfect polish.
More recently, over the past year or so, I have come to collect much more selectively, and I polish with more leniency. When picking up stones on the beach, I now discard many of them even though I know they will polish well. They include, for instance, white quartz and red jasper, excellent examples of which I already have. I aim to collect the most unusual and interesting ones, and the ones that have very few pits or cracks, if any. I then sort through these stones when I return to my accommodation at the beach, dry them and inspect them carefully – flaws show up much more clearly when the stone is dry. I tend to discard maybe one-quarter to one-third of the ones I have collected so the ones I bring home to polish are much more likely to be interesting and to polish successfully. And I can start tumbling most of these stones with 320 grade grit, skipping two stages and saving at least two weeks of total tumbling time.
I am also less severe in judging an acceptably polished stone. I will now be happy with a stone that still has some flaws, that is not completely smooth. This means that I am able to keep a wider range of stone types. Also, the end product will be a bit bigger as it has not been worn away as much. A stone is kept based on its interesting colour or pattern rather than its smoothness.
I mentioned towards the end of a previous post that I had met Maike and Martin, a young couple from Germany, on Gemstone Beach in March. I agreed to tumble-polish some stones for them. Today I finished the process, and Petra my wife will take the stones to Germany when she travels there in a couple of days.
Altogether, Maike and Martin collected 83 stones on Gemstone Beach. The largest is 6 cms by 3 cms, the smallest being about half the size of my small finger-nail. All 83 fitted nicely into a 3lb tumbling barrel. I am very impressed with the resulting product, an excellent set of polished Gemstone Beach “gems”! Maike and Martin collected well.
The following are photos of the original stones, dry, then how they looked after their first tumble in 320 grit, and then how they looked after their final polish:
The 83 stones as found on the beach.
After the first tumble in 320 grit.
After the final polish.
Firstly, the stones were tumbled in 320 grade silicon carbide for seven days, then tumbled in Sunlight soap for six hours. Secondly, they were in a five-micron tin oxide “pre-polish” tumble for five days, then tumbled in Sunlight soap for 16 hours. Thirdly, a one-micron tin-oxide “pro-polish” stage took eight days, followed by 27 hours in borax soap. The whole process took 22 days. This is probably the shortest time I have ever polished stones, but the outcome was very good. Initially the stones weighed 780 grams, finishing up at 689 grams, thus losing 10% of their mass, most of it in the 320 tumble stage.
The following photographs provide comparisons of some of the polished stones with how they looked initially, when found on Gemstone Beach. To start off with, here are three of the larger ones:
Maybe a kind of argillite, a mudstone.
Banded rhyolite stone.
Further comparisons for larger stones:
As found on the beach.
Polished.
Different textures.
As found on the beach.
As found on the beach.
Polished.
Some of the medium-sized stones:
Two polished stones.
Before polishing.
Before polishing.
Before polishing.
Polished.
As found on the beach.
Polished.
Smaller stones:
White quartz stones as they were on the beach – practically polished already!
Some other small stones from the beach.
Some small green stones from the beach.
The polished stones.
One of the stones is a small jasper button:
Before polishing.
The polished jasper stone is at the right.
Finally, some of the smallest stones collected by Maike and Martin:
Before polishing.
After polishing.
When packaging the stones to send to Germany, to complete Maike and Martin’s set of outstanding Gemstone Beach stones, I added a hydrogrossular garnet and a stone with a fossil worm cast. These are iconic Gemstone Beach gems, with the hydrogrossular garnet especially sought after, and the fossil worm cast being reasonably distinctive to this coast. As they were absent from Maike and Martin’s haul, I took the liberty of adding them to the package heading overseas.
White hydrogrossular garnet (left) and what is probably an argillite stone with a fossil worm cast (right).
Gemstone Beach, near Orepuki on the south coast, “is in a constant state of change with the surface changing from sand to stones with the storms and tides” (Southland website). This year, I spent three weeks in March in Southland, collecting beach stones, and I made five visits to Gemstone Beach. This year the beach offered lots and lots of good stones, maybe the most I have seen. As a result, I collected probably about 18 kilograms of stones from there to take home to polish. These included over 100 stones with fossil worm casts.
Gemstone Beach is just a kilometre from Orepuki, a small village on a sparsely settled part of the southern coast of New Zealand. Gold was mined in the district during the last two decades of the nineteenth century, and in the 1880s the southernmost Chinese settlement in the world was to be found there. It is said that semi-precious gems such as garnet, sapphire, jasper, quartz and semi-nephrite can be found on Gemstone Beach, although some of these are very rare. Quartz and jasper are reasonably common, and you can sometimes find hydrogrossular garnet stones and argillite stones containing fossil worm casts.
Location of Orepuki and Gemstone Beach on the Southland coast
TAUNOA STREAM
When you initially walk down from the car park and emerge onto Gemstone Beach (see map below), it can be a real disappointment if you’re expecting to see a lot of great stones. The immediate area is usually primarily sand, with only a handful of widely-spaced stones around. [NOTE: In the three years since I wrote this, there have been many times when there has been lots of stones on this part of the beach. They come and go from time to time.] Just to the left is a small (un-named) stream which many people go to in order to see if there are interesting stones there but it also sometimes disappoints.
Entrance area of Gemstone Beach – from Mapcarta
This photo (below), taken by me in February 2018, shows a family on the beach just a few metres away from the car park. Notice the wide scattering of stones – usually there are less than 10 per cent of this number in this area. The two people in the background are looking towards the un-named stream.
When you come onto the beach from the car park, about 200 metres to your right (in a north-west direction) is a stream that flows across the beach to the sea, Taunoa Stream (see map above). At times the depth of the stream water can be high enough to dissuade anyone wearing shoes from crossing, unless they take their shoes off. However, it is further along the beach beyond this stream that the stones will be found. At high tide, it can be impossible to ford the Taunoa Stream because of the waves rushing in to the foot of the nearby cliff. This year, the stream bed was full of stones, the water having swept the covering of sand from them. A significant part of my second visit to Gemstone Beach this month (March) was spent examining the stones in the stream.
Having crossed Taunoa Stream, looking upstream.
I always wear gumboots to make crossing the stream easier. Many interesting stones could be seen on the stream bed.
Standing in the Taunoa Stream at mid-tide, looking out to sea. At centre left are Martin and Maike, about whom more later.
NORTH-WEST OF TAUNOA STREAM
At times, one has to walk a long way (maybe 200 or 300 metres) past the Taunoa Stream to find stones (see photo below, left). This year, after only about 100 metres past the stream, large drifts of stones covered the beach (below, right).
April 2016 – a sandy beach.
March 2019 – a stony beach.
And the stones were scattered right up to the cliff face, unlike at other times when I have visited.
April 2016 – Few stones in the area near the cliff.
March 2019 – Many stones in the area near the cliff.
Each drift of stones on the beach consisted of a good layer of pebbles, some on the small side but many of a good polish-able size.
Gemstone Beach, looking back towards Taunoa Stream (at the small break in cliffs)
The edge of a drift – toe of gumboot at bottom centre.
.A drift of stones.
On the edge of a drift – dark red jasper pebble in centre.
THE WAIMEAMEA RIVER MOUTH
About one kilometre along the beach from the Taunoa Stream is the mouth of the small Waimeamea River.
Gemstone Beach from the car park to the mouth of the Waimeamea River. Source: Google Maps.
The Waimeamea River builds up a lagoon behind the large bank of stones thrown up by the sea. Source: Mapcarta.
Currently – and this was also the case when I was there in September 2018 – there is a large bank of stones along the beach, starting about 400 metres before the Waimeamea River mouth and continuing as far along the beach as I could see (some kilometres). The bank is quite high, maybe four or five metres in places, and up to 50 metres wide. Some of the stones here are bigger than those closer to Taunoa Stream, too big for my tumble polish barrels. But the bulk of them are much smaller, just right for the tumbler.
The high bank of stones that appears as one moves along the beach towards the Waimeamea River.
The top of the bank.
Stones on top of the bank, the large one in the centre being a brechia (a conglomerate with non-rounded stones in it).
Stones on top of the bank, the large one in the centre has fossil worm casts in it.
The stone bank holds back the waters of the river, preventing them from reaching the sea, creating a lagoon running parallel to the coast. However, water seeps under the stones to meet the incoming waves, the stones start to collapse, and eventually a channel appears for the river to flow out, as I had observed in September 2018.
March 2018 – The bank of stones is intact, holding back the Waimeamea River.
September 2018 – Waimeamea River has temporarily broken through the stone bank.
THREE ENCOUNTERS
Birds are perhaps the most common wildlife encountered on southern beaches. At the mouth of the Waimeamea River, I walked past some seagulls and terns, trying hard not to disturb them:
Further back down the beach, near the Taunoa Stream, in my second encounter, I met up with Maike and Martin, a young couple from Germany on holiday in the South Island. They were picking up interesting stones and asked me how they could get them polished. I volunteered to do a batch for them. I also gave them a short break from living out of their car, inviting them back to the crib at Riverton. Below are some of the stones I am in the process of polishing for them.
Martin & Maike from Germany.
The stones collected on Gemstone Beach by Martin & Maike.
See this Post to see how these stones looked after polishing.
My third encounter, from a distance, was with some horse riders, glimpsed as I left Gemstone Beach for the last time during this series of visits. They were moving towards the car park from the south-east of the beach, from the direction of Monkey Island. There were four riders on horses, one horse carrying a child being led, and a wagon drawn by two horses.
Horse riders and horse-drawn wagon on Gemstone beach.
Coser-up photo of horse riders and horse-drawn wagon on Gemstone beach.
NOTE: March 2021. Due to changes in the supply of grit and polish, plus a few other things, there are now six stages that I recommend instead of seven. The details are in UP-DATE OF “The Seven Stages in Tumble Polishing Stones” – One Less Stage. However, there are many useful practical suggestions in this original series so I have decided to leave it basically unchanged.
There are seven stages in the tumble polishing of stones. The first stage is acquiring the rough stones, stones of the right shape and condition and colour that show good promise for polishing. (Note that nearly all other accounts of tumble polishing don’t include stone collection as a stage.) Stage Two, for me, is tumbling the stones for about a week in 100 mesh silicon carbide grit, then tumbling them in a soap wash for a few hours. In Stage Three I repeat this process, using 220 mesh silicon carbide grit, while Stage Four is the same procedure with 320 silicon carbide grit. At this point, the stones should be shaped and smooth enough to begin actual polishing. I then use two polishing stages. Stage Five involves tumbling the stones in a tin oxide “Pre-Polish” powder (five microns in size) for three to five days, followed again by a few hours soap tumble. Stage Six is the “Pro-Polish” tumble, using tin oxide powder of one micron size, for at least one week. The final stage, Stage Seven, is a “burnishing” tumble for a week in borax. At every stage, stones are individually examined and may be set aside to repeat a stage or, more rarely, even skip a stage.
I emphasise that these seven stages describe what I normally do. However, I often start tumbling a newly collected smooth beach stone at Stage Four. Note that other tumble polishers often use different grits and polishes in different ways. What I am describing is what I do and how I do it.
For me, Stage One, stone collection, usually involves spending time on beaches, head down, occasionally bending over to pick up a stone worthy of collection. The best way to decide if a stone is worth polishing is to view it wet, so I often walk along the sea edge where the waves roll in then die out as they wash over the sand and stones. I will often take a promising dry stone to the wave edge so it can be wettened to bring out its colour. If it is raining, all the better as I then do not need to keep on checking for the next big wave that may wash in and wet my feet.
I often wear gumboots but sometimes even those are overwhelmed by an unexpectedly larger or more energetic wave.
Wringing out wet socks after a wave swept in further than expected and overwhelmed my gumboots. Bag of collected rocks beside me. This is at Orepuki (Gemstone Beach) near Riverton, 4 November 2017. Photo taken by Helen Hannah.
Clothes worn for stone collecting: usually warm clothes as beaches are often windy; gumboots or jandals depending on temperature; cap (if sunny) or woolen hat (if cold and cloudy); light waterproof coat and waterproof over-trousers if weather is wet.
Equipment used for stone collecting: small backpack to carry drinking water, food, camera, plastic collecting bags, and collected stones.
Kinds of stones worth collecting: those with interesting colours and patterns; the smoother the better; the harder the better; the more slippery the better; with a minimum of cracks and pits and jagged edges; not too big (as the tumble barrels are small) and not too small (as the polishing process wears away a proportion of the stone). When wet, you can see a stone’s colours but the cracks and pits in it are not so easy to see. When dry, the cracks and pits can be more easily seen, but the stone will look dull.
I mainly collect beach stones and river stones. They have the advantage of being smoother and more easily identifiable than stones or rocks found anywhere else. They are easier to tumble polish because their jagged edges have already been worn off.
Some beaches have just a scattering of stones along the sand – it is still possible to find some very good specimens here as you stroll along.
Other beaches have masses of stones. Sometimes a collector need just stand or sit there to find many good specimens.
Stone collecting means that you visit interesting and scenic places. During this trip to Riverton, I appreciated patterns on the sand at Henderson Bay, bird wildlife at the Back Beach, and the rising of a full moon over Taramea Bay.
Once the stones are collected, they need to be taken home. Sometimes, such as when I am travelling by aeroplane, that means putting them in a plastic container and then posting them. When I went to post some to my home in the North Island at a Post Shop in Gore, I was asked by the assistant, “Don’t they have any stones up there?” “Not like these, no,” I replied, and I showed her some polished ones I had in my pocket. She was amazed at their beauty and understood why I was doing such a strange thing as mailing what looked like ordinary everyday stones across the country.
The next stage in tumble polishing happens at home after I unpack the collected stones or after the Postie has delivered those I earlier put in the mail. Stage Two involves tumbling rough stones in water and a low grade abrasive grit. In the next Post I will describe the Riverton stones selected to go through the stages of tumbling to illustrate this series. I will then look at their first tumble, in The Seven Stages in Tumble Polishing Stones: Stage Two, 100 Grit Tumble, 15-25 November 2017.
I have recently returned from spending a week based in Riverton, visiting beaches in the area to collect stones for polishing. I brought home a total of 23 kgs of stones (14 kgs of which were posted) from six different beaches. The main collection sites were a handful of Riverton beaches as well as Orepuki, Bluff, and near Cosy Nook.
Orepuki Beach
Looking down on the “Back Beach” at Riverton
The small beach next to Cosy Nook – a stream flows through the seaweed, revealing stones
Stirling Point, Bluff, just under the famous signpost
Glass on the Stirling Point beach at Bluff
The beach stones amidst boulders at Stirling Point, Bluff
The 59 stones from Slapton Sands were put through the usual five-week cycle of tumble smoothing and polishing – one week each of tumbling with 100 grit, then 220 grit, then 320 grit, then a tin oxide pre-polish, then a tin oxide pro-polish:
Comparing some of the polished stones with what they looked like “in the rough”:
